Stern worked at Prestige, owned by One Savings Bank, for 30 years before announcing his departure in December last year.
“I am pleased to be entering a new chapter in an already strong professional relationship with Fluent Money particularly ahead of what looks set to be a significant year for the business and the wider sector,” said Stern.
“They have a fantastic team, which I hope to complement with my knowledge and experience in the second-charge mortgage sector.”
Tim Wheeldon, joint managing director at Fluent Money, said: “Simon has been a valued friend within the industry for many years and we’re delighted to be welcoming him to the company as a non-executive director.”
Wheeldon said Stern brings with him a ‘wealth of broker knowledge and insight’.